Features: ESD-Protected Analog Inputs
±15kV IEC 1000-4-2 Air-Gap Discharge
±8kV IEC 1000-4-2 Contact Discharge
Single-Supply Operation
+2.7V to +3.6V (MAX1233)
+4.75V to +5.25V (MAX1234)
4-Wire Touch-Screen Interface
Internal +1.0V/+2.5V Reference or External Reference (+1.0V to AVDD)
SPI™/QSPI™/MICROWIRE™-Compatible 10MHz Serial Interface
12-Bit, 50ksps ADC Measures Resistive Touch-Screen Position and Pressure
Two Auxiliary Analog Inputs
Two Battery Voltages (0.5V to 6V)
On-Chip Temperature
8-Bit DAC for LCD Bias Control
4 * 4 Keypad Programmable Controller Offers Up to Eight GPIO Pins
Automatic Detection of Screen Touch, Key Press, and End of Conversion
Programmable 8-, 10-, 12-Bit Resolution
Programmable Conversion Rates
AutoShutdown™ Between Conversions
Low Power
260µA at 50ksps
50µA at 10ksps
6µA at 1ksps
0.3µA Shutdown Current
28-Pin 5mm * 5mm QFN Package
ApplicationPersonal Digital Assistants
Pagers
Touch-Screen Monitors
Cellular Phones
MP3 Players
Portable Instruments
Point-of-Sale Terminals
Pinout
Specifications
| AVDD to GND............................................................-0.3V to +6V |
| DVDD to AVDD .......................................................-0.3V to +0.3V |
| Digital Inputs/Outputs to GND .................-0.3V to (DVDD + 0.3V) |
| X+, Y+, X-, Y-, AUX1, AUX2, |
| and REF to GND ..................................-0.3V to (AVDD + 0.3V) |
| BAT1, BAT2 to GND.................................................-0.3V to +6V |
| Maximum ESD per IEC 1000-4-2 (per MIL STD-883 HBM) |
| X+, X-, Y+, Y-, AUX1, AUX2, BAT1, BAT2......................±15kV |
| All Other Pins.....................................................................±2.5kV |
| Maximum Current into Any Pin............................................50mA |
| Continuous Power Dissipation (TA = +70°C) |
| 28-Pin QFN (derate 28.5mW/°C above +70°C) .................2W |
| Operating Temperature Range ...........................-40°C to +85°C |
| Storage Temperature Range .............................-60°C to +150°C |
| Lead Temperature (soldering, 10s) .................................+300°C |
DescriptionThe MAX1233/MAX1234 are complete PDA controllers in a 5mm * 5mm, 28-pin QFN package. They feature a 12-bit analog-to-digital converter (ADC), low on-resistance switches for driving resistive touch screens, an internal +1.0V/+2.5V or external reference, ±2°C accurate, on-chip temperature sensor, direct +6V battery monitor, keypad controller, 8-bit digital-to-analog converter (DAC), and a synchronous serial interface. Each of the keypad controllers' eight row and column inputs can be reconfigured as general-purpose parallel I/O pins (GPIO). All analog inputs are fully ESD protected, eliminating the need for external TransZorb™ devices.
The MAX1233/MAX1234 offer programmable resolution and sampling rates. Interrupts from the devices alert the host processor when data is ready, when the screen is touched, or a key press is detected. Softwareconfigurable scan control and internal timers give the user flexibility without burdening the host processor. These devices consume only 260µA at the maximum sampling rate of 50ksps. Supply current falls to below 50µA for sampling rates of 10ksps. The MAX1233/MAX1234 are guaranteed over the -40°C to +85°C temperature range.
MAX1234 Data Sheet
